Hollow toroidal or oval pneumatic tires of the type disclosed in U.S. Pat. No. 3,606,921, issued Sept. 21, 1971 to C. E. Grawey and assigned to the assignee of the present invention represent a considerable advancement in the art. However, these tires have a substantially nonexpandable inner peripheral mounting surface because of their construction which usually includes a pair of transversely spaced restraining hoops near the radially inner base of the sidewalls. Accordingly, the rim mounting arrangement for such tires has been heretofore a rim structure with axially interlocking flange halves for grippingly holding the tire thereon. Each of the flange halves includes an outwardly flared or conical peripheral surface, so that as they are axially moved together they entrap the tire within the peripheral concavity formed by the opposing flared surfaces. The difficulty with this is that there is an initial gap between the flange halves in which the tire can be pinched, and further the tire has a tendency to axially slip a disproportionate amount on each flared surface so that during installation of the flanges the tire tends to buckle or become offcentered. As a result, the fastening devices which are utilized to secure the flange halves together must be sequentially limitedly tightened with considerable care to minimize these difficulties. Another problem is that the rim structures must be heavy and rugged in construction in order to withstand the relatively high assembly loads at an increase in cost and at a reduction in serviceability thereof.
Further exemplifying the state of the art are U.S. Pat. Nos. 991,045 issued May 22, 1911 to J. H. Andrews et al; U.S. Pat. No. 1,160,222 issued Nov. 16, 1915 to J. H. Wagenhorst; U.S. Pat. No. 1,582,575 issued Apr. 27, 1926 to J. G. Casteran; and U.S. Pat. No. 3,291,171 issued Dec. 13, 1966 to W. E. F. Lehmann. However, as far as is known none of these references have tire rim mounting arrangements which exhibit the degree of expandable tire gripping fit required along with a simple, lightweight, and economical structure. In addition, the methods of installing the rim mounting arrangements within the tires are relatively complex.